Download YT Clip

ytclip.sh

#!/usr/bin/env bash
#
# ytclip: Download and clip a portion of a YouTube video into MP4.
# 
# Usage:
#   ytclip <YOUTUBE_URL> --from <TIME> --to <TIME>
# 
# <TIME> can be:
#   - S        (e.g. "75")
#   - M:S      (e.g. "2:38")
#   - H:M:S    (e.g. "01:02:03")
#
# Example:
#   ytclip "https://www.youtube.com/watch?v=7DV9SZgxegA" --from 2:38 --to 2:41
#
# Dependencies:
#   - yt-dlp   (https://github.com/yt-dlp/yt-dlp)
#   - ffmpeg   (https://ffmpeg.org/)

# ----------------------
# 1. Parse Arguments
# ----------------------

if [[ $# -lt 5 ]]; then
  echo "Usage: $0 <YOUTUBE_URL> --from <TIME> --to <TIME>"
  echo "Example: $0 \"https://youtu.be/XYZ\" --from 2:38 --to 2:41"
  exit 1
fi

YOUTUBE_URL="$1"
shift

FROM_TIME=""
TO_TIME=""

while [[ $# -gt 0 ]]; do
  case "$1" in
    --from)
      FROM_TIME="$2"
      shift 2
      ;;
    --to)
      TO_TIME="$2"
      shift 2
      ;;
    *)
      echo "Unknown option: $1"
      exit 1
      ;;
  esac
done

# Ensure all required fields are present
if [[ -z "$YOUTUBE_URL" || -z "$FROM_TIME" || -z "$TO_TIME" ]]; then
  echo "Error: Missing required arguments."
  echo "Usage: $0 <YOUTUBE_URL> --from <TIME> --to <TIME>"
  exit 1
fi

# ---------------------------------------
# 2. Convert Time Strings to Seconds
# ---------------------------------------

# This function accepts S, M:S, or H:M:S and converts to total integer seconds.
function hms_to_seconds() {
  local timestr="$1"
  local IFS=':'
  local parts=($timestr)  # Split on ':'
  local len=${#parts[@]}

  case $len in
    1)  # S
        echo "$((10#${parts[0]}))"
        ;;
    2)  # M:S
        echo "$((10#${parts[0]} * 60 + 10#${parts[1]}))"
        ;;
    3)  # H:M:S
        echo "$((10#${parts[0]} * 3600 + 10#${parts[1]} * 60 + 10#${parts[2]}))"
        ;;
    *)
      echo "Invalid time format: $timestr" >&2
      exit 1
      ;;
  esac
}

START_SEC=$(hms_to_seconds "$FROM_TIME")
END_SEC=$(hms_to_seconds "$TO_TIME")

# ---------------------------------------
# 3. Calculate Duration & Validate
# ---------------------------------------
if (( END_SEC <= START_SEC )); then
  echo "Error: End time must be greater than start time!"
  exit 1
fi

DURATION_SEC=$((END_SEC - START_SEC))

# -----------------------
# 4. Prepare Output
# -----------------------
CLIPS_DIR="$HOME/clips"
mkdir -p "$CLIPS_DIR"

TIMESTAMP="$(date +'%Y%m%d_%H%M%S')"
TEMP_FILE="$CLIPS_DIR/temp_${TIMESTAMP}.mp4"
OUTPUT_FILE="$CLIPS_DIR/clip_${TIMESTAMP}.mp4"

# -----------------------
# 5. Download via yt-dlp
# -----------------------
echo "Downloading video to $TEMP_FILE..."
yt-dlp --merge-output-format mp4 "$YOUTUBE_URL" -o "$TEMP_FILE"
if [[ $? -ne 0 ]]; then
  echo "Error: Download failed."
  exit 1
fi

# -----------------------
# 6. Use ffmpeg to Clip
# -----------------------
echo "Clipping from $FROM_TIME to $TO_TIME (duration: ${DURATION_SEC}s)..."
# Notice we put -ss AFTER -i for more accurate seeking
ffmpeg -hide_banner -loglevel error \
  -i "$TEMP_FILE" \
  -ss "$START_SEC" \
  -t "$DURATION_SEC" \
  -c copy \
  "$OUTPUT_FILE"

if [[ $? -ne 0 ]]; then
  echo "Error: ffmpeg clipping failed."
  exit 1
fi

# Remove the large downloaded video, keep only the clip
rm -f "$TEMP_FILE"

# -----------------------
# 7. Open Finder & Done
# -----------------------
open "$CLIPS_DIR"
echo "Done! Your clip is at: $OUTPUT_FILE"